mimxrt/mpconfigport: Add back lost uos.urandom().

It got lost in a clean-up session recently.

ports/mimxrt/mpconfigport.h

@@ -77,6 +77,7 @@ uint32_t trng_random_u32(void);
 #define MICROPY_PY_OS_DUPTERM               (3)
 #define MICROPY_PY_UOS_DUPTERM_NOTIFY       (1)
 #define MICROPY_PY_UOS_UNAME                (1)
+#define MICROPY_PY_UOS_URANDOM              (1)
 #define MICROPY_PY_URANDOM_SEED_INIT_FUNC   (trng_random_u32())
 #define MICROPY_PY_MACHINE                  (1)
 #define MICROPY_PY_MACHINE_PIN_MAKE_NEW     mp_pin_make_new